1. Field of the Invention
This invention relates to navigation systems. Specifically, this invention relates to a novel system and method that promotes safety in, and enhances the utility of, navigation systems.
2. Description of Related Art and General Background
Navigation systems assist users in finding their way from one location to another. In some systems, a user inputs a starting location and an intended destination, and the system, typically via algorithms acting on map databases, generates a sequence of directions that the user may follow to successfully reach the destination. These directions comprise one or more waypoints, which are points along the prescribed route that may bear significance to the route. For instance, if the directions prescribe that the user should turn right at the intersection of X and Y Streets, then that intersection may be a waypoint. In such systems, a user traversing the route must carefully follow the directions. Indeed, if the user veers off the route, the user easily may become lost; in unfamiliar surroundings, it is often difficult to return to the prescribed route.
More advanced systems employ Global Positioning System (GPS) technology to supply a user in close vicinity of the navigation device with real-time information about the user's geographic location. A GPS-equipped device receives signals transmitted by twenty-four NAVSTAR GPS satellites orbiting the earth, triangulates these signals, and computes the location of the device in terms of coordinates. Because the coordinates are themselves of little significance to most users, GPS systems may provide a visual representation of a user's location, represented by a cursor overlaid on a map of the region in which the user is presently located.
Hybrid systems combine the functionality of the above-described systems. A user inputs a desired destination, a GPS receiver in the navigation device computes the current location of the device, software determines a route for the user, and the device outputs a set of directions for the user to follow. A map of the surroundings encompassing the route may be shown on a video display, as may the current location of the device. The current location may be represented by a cursor overlaid on the map. Additionally, the prescribed route may be superimposed on the map. Both the map and cursor may be dynamically updated as the user traverses the route. Nevertheless, if the user fails to constantly monitor the position of the cursor on the map, the user may not realize that he has deviated from the prescribed route. When this discovery is made, significant travel time may have been lost, and a less advantageous route may be the only alternative.
When users travel across great distances or vacation in obscure locales, navigation devices must display maps associated therewith. Accordingly, large data sets are needed. Most conventional navigation systems have relied on mass-storage means, such as CD-ROMs, to fulfill this need, but many region-specific CD-ROMs must be purchased at great expense. The map information contained within the CD-ROMs may become outdated with the construction of new thoroughfares. In addition, the map information may become unreliable when, for instance, temporary road construction, traffic conditions, or natural disasters render legs of a route inaccessible or otherwise undesirable. Various solutions have been proposed, including acquiring map data from remote locations via radio transmission or similar means. Unfortunately, these proposals fail to sufficiently limit the character, quantity, and frequency of transmissions from the remote location to the user's location and back.
More fundamentally, these proposals are lacking in their failure to sufficiently protect the well-being of the user. In particular, when a user inadvertently deviates from a prescribed route, the user may be inconvenienced by travel delays. Further, at night, the likelihood of having an accident may increase if the user has ventured onto secondary roads in need of repair or roads in which lighting is inadequate.
Moreover, the problem of the misguided traveler exists alongside an even more pervasive one: the problem of the distracted traveler. For example, when the GPS device resides in a car, a driver who is lost may have to physically input new commands, such as a request to generate a new route from the current position to the original destination. By physically operating the device when driving, the driver may become distracted, making such operations potentially dangerous.
Furthermore, it is desirable that those in the public-at-large, including persons with disabilities, are able to fully avail themselves of the functionality of a navigation system.
Therefore, what is needed is a system and method that promotes safety in, and enhances the utility of, navigation systems.